According to Mark Betner, heavy-duty motor oil manager and lubrication specialist for Citgo Petroleum Corp., the primary consideration is that lubricants be of proper viscosity to handle low ambient temperatures.
"Most OEMs have low temperature viscosity recommendations for engine oils, hydraulic fluids, transmission fluids and gear lubricants," Betner says. "You should read and follow their recommendations, but don't hesitate to call your lubricant supplier for help if you don't understand the OEM guidelines or have application questions."
As temperatures dips to near zero, 15W-40 engine oil typically becomes too viscous to achieve effective lubrication. Betner recommends use of SAE 10W-30 and 5W-40 for winter use in both gasoline and diesel engines to provide easier cold cranking and start-up.
Betner explains the generally known fact that wear can accelerate during start in an internal combustion engine, whether gasoline or diesel-fueled, due to lack of lubrication and poor oil fluidity. The lower viscosity of properly blended heavy-duty 5W-40 engine oil results in quicker oil pick up and oil film protection in the critical engine wear zones during cold weather start ups, while maintaining excellent oil film protection at high operating temperatures. The result is less incidence of metal-to-metal contact, regardless of the temperature.
More information about cold-weather lubrication can be found on Citgo’s website.